[seqfan] Interesting discovery by Dan Preston concerning a Recaman-like sequence

[Neil Sloane]

Dear Seq Fans

(By the way, Russ Cox fixed the "disk full" problem early this morning, so
the OEIS is back to normal).

Dan Preston just wrote to me about an interesting discovery he has made.
The Recaman-variant A228474 seems to have an extraordinary jump at n=11281
(or, less likely, it doesn't converge there)
He finds the following values:

WreckerBall[11276] = 632100
WreckerBall[11277] = 632102
WreckerBall[11278] = 632104
WreckerBall[11279] = 632106
WreckerBall[11280] = 631064
WreckerBall[11281] still calculating after 32,200,000,000 steps...
//Segmentation fault: 11
WreckerBall[11282] = 631072
WreckerBall[11283] = 631070
WreckerBall[11284] = 19675891
WreckerBall[11285] = 631078
WreckerBall[11286] = 631076

He found other indices at 22044, 36618 which also fail to converge in a
timely manner.

Nice problem!

By the way, I changed the definition of that seq to add an escape clause:
a(n) = -1 if the trajectory never reaches 0.

Best regards
Neil

Neil J. A. Sloane, President, OEIS Foundation.
11 South Adelaide Avenue, Highland Park, NJ 08904, USA.
Also Visiting Scientist, Math. Dept., Rutgers University, Piscataway, NJ.
Phone: 732 828 6098; home page: http://NeilSloane.com
Email: njasloane at gmail.com